The innate immune system detects viral infection by recognizing various viral components and triggers antiviral responses.  Like the toll-like receptor 3 (TLR3), the cytoplasmic helicase retinoic acid inducible gene protein 1 (RIG-1) recognizes double-stranded (ds) RNA, a molecular pattern associated with viral infection.  Unlike TLR3 however, RIG-1 activates the kinases TBK1 and IKKepsilon through the adaptor protein IPS-1.  These kinases then phosphorylate the transcription factors IRF-3 and IRF-7 which are essential for the expression of type-I interferons.  RIG-1 is required for the production of interferons in response to RNA viruses including paramyxoviruses, influenza virus, and Japanese encephalitis virus.